Balloon catheters including inflatable balloons can, for instance, be taken from EP 402964 B1. The known balloon catheter serves for coronary sinus occlusion, wherein diagnostically valuable signals can be obtained by a plurality of sensors and the inflation of the balloon can be controlled, in particular, with a view to achieving retroperfusion. Such a balloon catheter is also known as a multi-lumen catheter, whose distal end projects, for instance, into the coronary sinus of the heart, while the proximal end of the catheter is connected with a pump for inflating the balloon. Wires for electrically contacting sensors can be conducted through further lumens arranged coaxially or in parallel with the lumen that serves to inflate the expandable balloon. Via such further lumens, cardioplegic or thrombolytic, or other pharmacologically active substances suitable for retroperfusion in ischemic tissue, can also be introduced.
In order to supply ischemic tissue with blood by retrograde perfusion, it has already been proposed to use an inflatable balloon fixed to the end of a catheter to intermittently occlude the coronary sinus. The blood pressure in the coronary sinus rises during the occlusion at every heart beat so as to cause blood reaching the coronary sinus through the healthy tissue of the heart muscle to be flushed back into the ischemic tissue. Another effect of intermittent occlusion is the influence on the pressure regulation due to the feedback mechanism by neuro-stimulative effects. For such intermittent coronary sinus occlusion, the balloon end of the catheter is inserted either percutaneously or surgically. The other end of the catheter is supplied by a pump with a gas or fluid which causes the cyclic inflation and deflation of the balloon. A device for the retroperfusion of coronary veins is, for instance, known from WO 2005/120602 A1, by which a pressure-controlled, intermittent coronary sinus occlusion can be performed. In that device and the corresponding method for determining the optimum times for triggering and releasing the occlusion, pressure parameters like the speeds of the pressure increase and pressure drop were determined and subjected to relatively complex processing.
For the percutaneous insertion of a catheter, it is proceeded in a manner that the catheter is guided via the inferior or the superior cava vein into the right atrium of the heart, into which the coronary sinus runs. Due to the position of the mouth of the superior cava vein or inferior cava vein, respectively, relative to the mouth of the coronary sinus, the introduction of the catheter into the coronary sinus requires considerable skill from the cardiologist in order to direct the tip of the catheter, or a guide wire or a guide sleeve, into the coronary sinus in such a manner as to enable the subsequent introduction of the catheter along with the occlusion device. In fact, it frequently happened that several attempts of introduction into the coronary sinus had to be made, which considerably extended the duration of treatment and, hence, the strain on the patient.
Another problem involved in balloon catheters used for the intermittent occlusion of the coronary sinus resides in that blood backed up during the occlusion would exert pressure on the balloon, and hence on the catheter, thus eventually causing the catheter to slip back or kink within the vessel.